Hi Mark... there is a current discussion on the Training Discussion regarding the length of a workout. Answers are between 1 hour and 2.5 hours.
I was under the impression that after about 1.5 hours of training the cortisol levels start to negate some of the benefits of that workout.
Could you (or others) explain how cortisol negatively-affects the person and what we should be doing to minimise the cortisol (if possible).
Cheers.